This invention relates to high-speed positioning apparatuses useful for nano- and micro-scale technological applications, such as semiconductor wafer processing, chemical substance deposition, and experimentation with bio-organic materials, scanning microscopy, or other applications which include macro scale transport equipment and positioning devices.
Nano-technological applications often require high precision positioning of substrate combined with large range of motion. Time between elementary processing steps always needs to be minimal to accommodate low contamination level, small feature sizes and process throughput.
Typical example of nano-technological process is micro-contact deposition of chemicals using micro-stamps and cantilever type devices. Electron-beam type devices that operate on principle of scanning tunneling microscope is another typical example.
Existing positioning equipment usually use combinations of slow large range positioning mechanism with relatively fast micro-range stage. Cahill, Hunter, U.S. Pat. No. 6,144,118, describe an apparatus capable of moving in X, Y, and yaw in limited range with moderate speed. It uses separate mechanical stage for slow large range motion. Apparatus uses permanent magnets as a part of movable part of the stage. Such design limits range of achievable accelerations for the stage due too high mass of the magnets and their limited magnetic field.
Hollings, U.S. Pat. No. 5,153,494 describes an apparatus capable of moving with extreme accelerations in X, Y, and yaw in limited range. The apparatus uses electrically powered conductive coils as a part of movable part of the stage. Such design requires electrical wires to be attached to the movable part, which restricts reliability of the apparatus. Repetitive motions of the stage cause the wires to break. It is also limiting supply currents to the stage, because high current require thicker wires with lower flexibility.
Trumper, U.S. Pat. No. 5,196,745, describes an apparatus capable of motion in 200 to 300 mm range in one or two degrees of freedom. Linear motions of the stage provided by permanent magnets attached to the movable part. Such design carries the same restrictions on maximum achievable acceleration.